Extra‐cellular dopamine increases in the paraventricular nucleus of male rats during sexual activity

Abstract

Dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations were measured in the dialysate obtained with vertical microdialysis probes implanted into the paraventricular nucleus of the hypothalamus of sexually potent male rats. Animals showed noncontact erections when put in the presence of, and copulated with a receptive (ovarietomized oestrogen and progesterone primed) female rat. Dopamine and DOPAC concentrations in the paraventricular dialysate increased 140% and 19%, respectively, above baseline values during exposure to the receptive female and 280% and 31%, respectively, during copulation. No changes in dopamine and DOPAC concentrations were detected in the paraventricular dialysate when sexually potent male rats were exposed to nonreceptive (ovariectomized not oestrogen plus progesterone primed) female rats. These results confirm the involvement of the paraventricular nucleus in control of erectile function and copulatory behaviour and show for the first time that dopamine neurotransmission is increased in this hypothalamic nucleus when erection occurs in physiological contexts.

Fos responses of dopamine neurons to sociosexual stimuli in male zebra finches

“…Administrations of the DA agonist apomorphine into the medial POA facilitate sexual behavior in male rats (Hull et al, 1986;Dominguez et al, 2001), whereas injections of the DA antagonist cis-flupenthixol into the medial POA reduce ejaculations, copulation rate, erections and penile movements before copulation, and sexual motivation (Pehek et al, 1988;Warner et al, 1991). Extracellular DA in male rats is increased in the medial POA during copulation and exposure to a receptive female (Hull et al, 1995), and in the paraventricular nucleus of the hypothalamus during copulation (Melis et al, 2003). Additional DA effects on sexual behavior are likely exerted by the mesolimbic and nigrostriatal systems, which respectively influence motivation and motor functions (reviews: Hull et al, 2004;Dominguez and Hull, 2005).…”

“…This colocalization decreased in response to all conspecific stimuli except fighting, and did not decrease following exposure to a heterospecific male. Keywords dopamine; forebrain; aggression; sexual behavior; tyrosine hydroxylase; Fos Dopamine (DA) is known to influence a variety of social behaviors, particularly male sexual behavior, in multiple vertebrate groups (Warner et al, 1991;Pomerantz, 1992;Absil et al, 1994;Hull et al, 1995;Dominguez et al, 2001;Woolley et al, 2001;Melis et al, 2003;Charlier et al, 2005), and DA cells are distributed in homologous groups across the vertebrate classes (Bailhache and Balthazart, 1993;Bottjer, 1993;Gonzalez and Smeets, 1994;Reiner et al, 1994;Tillet, 1994;Appeltants et al, 2001;Adrio et al, 2002). This similarity across vertebrates is particularly clear when comparing mammals and birds, which each have dopaminergic neurons (immunopositive for tyrosine hydroxylase, TH, and immunonegative for dopamine β-hydroxylase) localized to eight populations of the basal forebrain and brainstem numbered A8 through A15 (Reiner et al, 1994;Tillet, 1994).…”

Effects of acute and chronic apomorphine on sex behavior and copulation-induced neural activation in the male rat

“…Concerning copulatory behavior, the paraventricular nucleus of the hypothalamus appears to have a specific function in penile erection and seminal emission mechanisms (Arezki et al, 1985;Argiolas et al, 1987;Giuliano and Allard, 2001;Lowry et al, 2003;Melis et al, 1992bMelis et al, , 1996Melis et al, , 2001Melis et al, , 2003Pehek et al, 1989;Tian et al, 1991). The effects of apomorphine administration, applied systemically, intracerebroventricularly or locally, have shown convincingly that dopaminergic receptors in the paraventricular nucleus of the hypothalamus, probably of the D 4 -type located on oxytocinergic neurons (Melis et al, 1992a, are crucial, although with peripheral administration a direct pro-erectile effect on the sacral parasympathetic nucleus may play an additional role (Giuliano et al, 2002).…”

“…Apparently, the paraventricular hypothalamic nucleus, especially its oxytocinergic neurons, play an eminent role in the control of erectile function Melis, 2004, 2005;Martino et al, 2005;Succu et al, 2007). Extracellular dopamine levels increase in the medial preoptic area (Hull et al, 1993), nucleus accumbens (Pfaus et al, 1990;Pleim et al, 1990) and in the paraventricular hypothalamic nucleus (Melis et al, 2003) during sexual activity. The increased dopaminergic transmission in the nucleus accumbens appears to be controlled by lateral hypothalamic serotonin activity (Hull et al, 2004;Lorrain et al, 1999), and in the medial preoptic nucleus by activity of the medial amygdala (Dominguez et al, 2001).…”

Chemosensory Cues are Essential for Mating-Induced Dopamine Release in MPOA of Male Syrian Hamsters

“…As measured by in vivo voltammetry (Louilot et al, 1991) or microdialysis in male rats, noncontact exposure to a female elicits DA release in MPOA; copulation further stimulates MPOA DA release. DA is also released with mating and sexually relevant stimuli in other forebrain sites, including the nucleus accumbens (Mitchell and Gratton, 1991) and the paraventricular hypothalamic nucleus (Melis et al, 2003).…”